Design concepts for knowledge-based route guidance systems

Positioning, location, navigation, route guidance, and optimal route determination are defined as the principal tasks performed in automatic vehicle location (AVL) systems. Land-based AVL systems are shown to have two basic configurations: stand-alone and dispatch. The automation of the principal AVL tasks in a real-time environment is described. Automation is achieved through building an AVL system knowledge base of rules and facts. Individual actions are thus automatically controlled and managed in an optimal manner. In this process, the type of AVL system and the underlying application is taken into account. The authors also address coupled systems, in which numeric processes and symbolic processes are combined into one integrated unit